1. Field of the Invention
This invention relates to cost/benefit analysis in manufacturing, and more particularly to a method and system for evaluating costs and/or benefits of various possible configurations of a manufactured product.
2. Description of the Related Art
The following descriptions and examples are not admitted to be prior art by virtue of their inclusion within this section.
Manufacturing of products typically involves repeated upgrading of a product over time. One reason for such upgrading can be consumer demand for improved products as better technology becomes available. For example, the operating speeds available for personal computers have increased more than tenfold in the decade from 1990 to 2000. Upgrading of a product can also make the product less expensive to produce in some cases, leading to higher profits. In integrated circuit manufacturing, for example, upgrading often involves producing circuits having smaller geometries, such that more of the circuits fit on a single semiconductor wafer. If any additional cost of manufacturing a wafer with such smaller-geometry circuits is smaller than the increased income realized from producing more circuits per wafer, the upgraded circuits are less expensive to produce. Of course, many different motivations may be involved in a decision to upgrade a manufactured product. For example, an upgrade to smaller-geometry circuits as described above may also provide other advantages which may lead to increased income, such as increased circuit speed, reduced weight or power consumption, or suitability for a new application or market.
In the case of a relatively complex manufactured product, many different configurations of the product are possible. A computer, for example, typically includes multiple components or modules, such as processor, memory, and peripheral driver chips. There are generally multiple available variations for each of these components or modules, and therefore many unique combinations, or configurations, of the computer are possible. An integrated circuit may contain millions of interconnected transistors, formed using multiple masking layers. The masks used in the circuit's fabrication are generated using an arrangement of the transistors (and other circuit components) known as a layout. Some of the constraints used to arrive at the layout are embodied in a set of rules called design rules, which may take various forms. A design rule could be a dimension of a particular feature, such a gate width, or a relationship between features, such as an “enclosure”, or amount of overlap between a metal in a contact region and an underlying conductive via. Furthermore, a design rule could be a non-numerical rule, such as a requirement that an interconnect line in one layer not intersect with one in a different layer. A set of design rules is used when drawing a layout, or possible configuration, of the integrated circuit. Because an integrated circuit layout can easily be subject to more than 50 design rules, multiple different configurations are possible.
This multitude of possible configurations can make it difficult to determine the most cost-effective configuration for an upgraded product. Decisions as to upgraded product configurations are often made in an ad hoc manner, without a consistent approach to comparison of possible configurations. It would therefore be desirable to develop a method and system for consistent evaluation of possible upgraded product configurations. The desired method should provide information on the cost-effectiveness of proposed product upgrade configurations, as compared either to other configurations or to a non-upgraded product.